To adjust the motor mounts I just got a 14mm (I think 14mm or what ever fits) socket and grinded it down to where there were two "stubs" that could grab the motor mount adjuster and it worked good.
Premature belt failure can be so many things, need to know your clutching as it sits, which weights, where are they loaded, what helix, what twist, etc...
One thing people overlook when finding out what is causing belt failure is belt slip from snow getting in the clutches. We've found that pluging all the vents around the clutch will actually increase belt life by keeping snow from getting through the vents and slipping the belt when riding in the mountains.